1. Field of the Invention
The present invention relates, in general, to vehicle sun visors installed within the passenger compartment of a car and, more particularly, to a vehicle sun visor with a radio absorptive conductor acting as a radio antenna.
2. Description of the Prior Art
As well known to those skilled in the art, cars are conventionally equipped with onboard radio systems and sun visors for allowing people to conveniently and safely drive their cars. It is necessary for such an onboard radio system to be provided with an antenna for improving the reception sensitivity of the system and allowing people to enjoy clear sound quality from the system while driving a car.
Several types of vehicle antennas, for example, telescopic antennas, fixed rod antennas and film antennas, have been proposed and used.
Such a telescopic antenna is conventionally installed on a fender of a car, while such a fixed rod antenna is exteriorly installed on the roof, the rear window panel or the chassis of a car. The conventional film antenna is formed by coating a line-shaped conductive material in a zigzag arrangement on the interior surface of a windshield, a rear window panel, or a window glass.
The above-mentioned vehicle antennas individually have advantages and problems as follows.
That is, the fixed rod antenna is inexpensive in the manufacturing cost. However, such an antenna spoils the appearance of a car and may be easily broken since it is always exposed to the outside of the car.
On the other hand, the telescopic antenna is designed to telescopically extend from a fender when it is used and to be fully retracted into the fender when it is not used. The telescopic antenna is thus advantageous in that it is free from spoiling the appearance of a car. However, this type of antenna is problematic in that it forces a designer to necessarily consider the position and space for the antenna while designing a car since the antenna has to be installed on a fender while accomplishing a telescopic structure. It is also necessary for the telescopic antenna to be provided with a fixing structure, such as a mount bracket. Such a fixing structure in addition to the telescopic structure for the antenna increases the manufacturing cost of the antenna and complicates the process of manufacturing a car. The complicated process of manufacturing a car finally increases the assembling cost of the car.
Another problem of the telescopic antenna resides in that the telescopic structure of the antenna may be easily broken. When the antenna is fully extended outside a fender, the antenna may be unexpectedly broken in the same manner as that described for the fixed rod antenna. When the telescopic antenna is unexpectedly broken, it is necessary to completely replace the broken antenna with a new antenna incurring extra expense on the owner. This finally increases the maintenance cost of the antenna.
Since the film antenna is provided within the passenger compartment of a car, the antenna is not easily broken due to external impact and is free from spoiling the appearance of the car. However, it is necessary for the film antenna to be precisely coated on a glass in a desired arrangement. Therefore, this type of antenna is expensive. Another problem of the film antenna resides in that the antenna may be broken when a glass coated with the film antenna is broken.
In addition, sun visors, installed on the front portion of the interior ceiling within the passenger compartment of a car, are used for shielding the eyes of a driver from direct sunlight or glare.
Of course, a variety of sun visors have been proposed. Such visors may be appropriately selected by users in accordance with models of cars. However, most visors comprise longitudinal rigid panels and are designed to be rotatably mounted to the front portion of the interior ceiling at positions around the top edge of a windshield.
Such known sun visors are originally designed to effectively shield the eyes of a driver from direct sunlight or glare as described above, but may be provided with a clip capable of clipping a small-sized sheet material or with a mirror for allowing a driver to collaterally use it. However, the use of the sun visors is undesirably limited, and so it is necessary for designers to make the visors to be more effectively and more widely used in addition to the original use of the visors.